The blind including sightless and asthenopic persons are the weakest handicapped persons and need education to improve their life abilities. Conventional educations designed for the blind do not provide any effective methods to aim at the asthenopic persons having limited sight. Thus, those asthenopic persons have to learn Braille like those blinds who are totally sightless. Recently, some special education methods in view of asthenopic persons are desirable and those asthenopic persons are encouraged to use their limited sight to learn normal characters, instead of Braille, using magnifying glasses, cable television system with magnifying function, telescopes and special reading glasses or the like. However, since it is quite easy to feel tired to use eyes for reading, appropriate reading methods and devices are needed.
Braille is a type of symbols each of which consists of six projected dots. The basic structure of the international standard Braille consists of six projected dots (). When writing, a sheet of Braille paper is attached to a Braille plate on which circular doted-recesses are formed and using a Braille stylus to press the corresponding points of the recesses to form projections on the paper. When reading, the paper should be reversed. If any error is found, the correction of the error is time-cost and the process of the correction is complicated. A conventional Braille plate consists of a top board and a bottom board which are hinged with each other on one side. A sheet of Braille paper between the two boards is “written” with a Braille stylus through rectangular openings formed on the top board and circular recesses formed on the bottom board to form projections on the sheet of paper. Those projections arranged in light of the Braille rules can be touched by hands for reading. Such Braille writing device is costly. And, it is very hard to fix the paper on the device.
On the other hand, listening is the best choice for the blind to “read”. However, none of the Braille writing devices is able to provide such functions like processing the input Braille and outputting the input Braille by speaking. Recently, computers and palmtops called PDA are widely used in our life so that it is possible to incorporating the electronic technology and computer technology into a Braille writing device.